Wondered for many moons how much QA differs in lens manufacturing. Mike
Hatem noted significant performance differences in Zuiko 21/2's. Much
grousing on several Canyon L lenses with many reports of bad apples.
Whether the QA is bad or just the # sold and who they get sold to
(pixel peepers) is an open question . The below analysis seems to raise
as many questions as it answers.
Where is the source of the variability?---cam is clearly one. On repeat
with a top dog sample---less impressive results---regression to the
mean? There is clearly even registration distance manufacturing
tolerances as Zeiss often makes lenses that focus past infinity to
allow for this. They say if it bothers the customer they will adjust it
for your cam -no charge.
It does confirm that 10X LV manual focusing is more precise than
AF--for a target at least.
http://www.lensrentals.com/blog/2011/10/notes-on-lens-and-camera-variation
No none seems to put a lens on a scanning slit optical bench anymore
but measure system performance. For fun looked into for a minute the
fully automated Zeiss K8 system: Base price about 194K euro.
There are a few options which are: Image height measuring option,
4,100,-; Azimuth measuring option, 4,100,-; Collimator option 150mm f=
1.2m, 7,800,-; Collimator option 150mm f= 2.25m; "on request". So in
total US Dollars, figure about $280K. Hmmm, take a pass.
Wonder what it would show for a similar test, however.
Don't want any bad apples, Mike
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